Palbociclib in combination with simvastatin induce severe rhabdomyolysis: a case report

Profile of adverse drug reactions reported via the Continuum+ platform: Results from three-year regional follow-up

In 2017, the Continuum+ platform was launched to provide a monitoring solution to home-based cancer care patients: AKO@dom monitoring. This platform also offers the follow-up of adverse drug reactions (ADRs) via direct notification to regional centers of pharmacovigilance (RCPVs). According to previous studies, the AKO@dom monitoring has successfully maintained treatment at the maximum effective dosage, managing ADRs and patient satisfaction. However, on the pharmacovigilance side, opinions are more divided. Due to the launch of the AKO@dom-PICTO experimentation in December 2021, in which our RCPV takes part, and to provide more data on pharmacovigilance, we decided to conduct a descriptive analysis of cases reported to our RCPV via the Continuum+ platform between 2019 and 2022. During these three years, we analyzed 1070 events, corresponding to 37 patients. Patients were primarily women (74.8%) aged around seventy with breast cancer. The most used drugs were tyrosine kinase inhibitors: palbociclib (29.7%), axitinib (16.2%), and cabozantinib (13.2%). Patients had an average of 8 ADRs, including one serious and/or unexpected ADR. Although the Continuum+ platform makes it possible to considerably limit under-reporting in pharmacovigilance, it has shortcomings. The lack of medical elements and context in notifications is a massive problem for analyzing pharmacovigilance reports. Improved access to the platform's medical information for RCPVs and pharmacovigilance training for healthcare professionals would make Continuum+ a helpful tool in pharmacovigilance.

Predicting drug-drug interactions in breast cancer patients treated with CDK4/6 inhibitors and forward planning

INTRODUCTION

Cyclin-dependent kinase (CDK) 4/6 inhibitors are cornerstones in the treatment of Hormone Receptor (HR) positive and Human Epidermal Growth factor (HER2) negative metastatic breast cancer. Given their widespread use in the metastatic setting and emerging use in the adjuvant setting, studying drug-drug interactions (DDI) of these medications is of utmost importance.

AREAS COVERED

This review provides key background information on the CDK4/6 inhibitors, palbociclib, ribociclib, and abemaciclib. We discuss drug-drug interactions including those with proton pump inhibitors as well as CYP3A substrates, inhibitors, and inducers. We describe the effect of these drugs on membrane transporters and their substrates as well as those drugs that increase risk of CDK4/6 toxicities. Finally, we explore future directions for strategies to minimize drug-drug interactions.

EXPERT OPINION

It is crucial to be mindful of medications that may interfere with drug absorption, such as proton pump inhibitors, as well as those that interfere with drug metabolism, such as CYP3A4 inhibitors and inducers. Additionally, special consideration should be given to populations at higher risk for polypharmacy, such as older patients with greater comorbidities. These interactions and patient characteristics should be considered when developing individual treatment plans with CDK4/6 inhibitors.

CDK4/6 inhibitors in the treatment of metastatic breast cancer: Focus on toxicity and safety

The development of oral cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitors, including palbociclib, ribociclib, and abemaciclib, has revolutionized the treatment landscape for patients with hormone-receptor-positive (HR+) and human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (BC). When combined with an aromatase inhibitor or fulvestrant, these agents have been approved as first-line therapy in the metastatic setting. Abemaciclib has also gained FDA approval for patients with HR-positive, HER2-negative, node-positive, early BC at high risk of recurrence. Moreover, ribociclib has recently improved disease-free survival in patients with stage II or III HR+/HER2-negative early BC. CDK4/6 inhibitors have favorable safety profiles. However, the available agents have different toxicity profiles that must be clearly discussed with the patients for optimal clinical decisions. This manuscript aims to review CDK4/6 inhibitor-related treatment-associated adverse events, identify risk factors for intolerable adverse events, and assess their safety in special patient populations such as the elderly and those with renal insufficiency. Enhanced knowledge and understanding of CDK4/6 inhibitor-related toxicities can improve treatment strategies and ultimately enhance patient care.

Ribociclib may potentiate rosuvastatin effect in causing late onset rhabdomyolysis

A woman in her 50s with metastatic hormone receptor positive breast cancer developed rhabdomyolysis and subsequent acute kidney injury while on a combination of ribociclib and rosuvastatin therapy. She had been taking both medications long term and had recently recommenced her ribociclib at her usual dose after a routine 1 week break. Cyclin-dependent kinase 4/6 inhibitors have been implicated in causing rhabdomyolysis by potentiating statin effect by way of inhibition of cytochrome P450 enzymatic action and decreasing hepatic membrane transporter function. This is the first case in which the combination of ribociclib and rosuvastatin has been shown to cause this adverse effect. It is also one of the first to demonstrate this effect occurring years after commencement of therapy. Continued vigilance for this side effect should be maintained long term.

Foot drop secondary to rhabdomyolysis: improved foot dorsiflexion and gait after neurolysis and distal nerve transfer-a case series and literature review

Rhabdomyolysis is a triad syndrome of myalgia, muscle weakness and myoglobinuria due to muscle necrosis. Trauma, exertions, strenuous exercise, infections, metabolic and electrolyte disorders, drug overdoses, toxins and genetic defects are the most common causes of rhabdomyolysis. The etiologies of foot drop are diverse. A few cases of rhabdomyolysis-associated foot drop are reported in the literature. We present five patients with foot drop secondary to rhabdomyolysis; two underwent neurolysis and distal nerve transfer (superficial peroneal nerve to the deep peroneal nerve) surgeries and follow-up evaluations. We found five-foot drop patients secondary to rhabdomyolysis among the 1022-foot drop patients who consulted our clinic since 2004, representing a 0.5% incidence. In two patients, rhabdomyolysis was caused by drug overdose and abuse. In the other three patients, the causes were an assault with a hip injury, a prolonged hospitalization due to multiple illnesses, and an unknown cause with compartment syndrome. Pre-operatively, a 35-year-old male patient had aspiration pneumonia, rhabdomyolysis and foot drop resulting from prolonged ICU hospitalization and a medically induced coma due to a drug overdose. The second patient (a 48-year-old male) had no history of trauma but had a sudden onset of right foot drop after compartment syndrome following the insidious onset of rhabdomyolysis. Both patients had difficulty dorsiflexing their involved foot and walked with a steppage gait before surgery. In addition, the 48-year-old patient had foot slapping while walking. However, both patients had strong plantar flexion (5/5). After 14 and 17 months of surgery, both patients had improved foot dorsiflexion to an MRC grade of 4/5 with an improved gait cycle and walked with no or minimal slapping, respectively. Distal motor nerve transfers in the lower limb facilitate faster recovery and less surgical dissection because of the shorter regeneration distance from the donor axons to the targeted motor end plates through residual neural network connections and descending motor signals.

Rhabdomyolysis Induced by the Interaction Between Ribociclib and Statins- Case Report and Literature Review

Cyclin-dependent kinase (CDK) 4/6 inhibitors given with endocrine therapy are standard of care for the treatment of women with advanced hormone receptor (HR) positive and human epidermal growth factor receptor 2 (HER-2) negative breast cancer. Ribociclib is a CDK 4/6 inhibitor with moderate to solid inhibition of CYP3A4, a member of the cytochrome P450 family oxidase system, which may lead to interactions with medicinal substrates that are metabolized via CYP3A4. Statins are among the most widely prescribed medications worldwide, predominantly metabolized by the CYP3A4 isoenzyme. Rhabdomyolysis is a known rare side effect of statins, commonly triggered by drug interactions. We report a case of a 73-year-old woman with metastatic HR-positive and HER-2 negative breast cancer who developed rhabdomyolysis and acute kidney injury due to interaction between simvastatin and ribociclib with a literature review.

Severe toxic rhabdomyolysis under combined palbociclib and simvastatin treatment: A case report

We report the fourth described case of severe toxic rhabdomyolysis occurring in an 81-year-old woman caused by the concomitant administration of palbociclib taken at the usual dosage (125 mg per day) and simvastatin. To the best of our knowledge, this is the first reported case successfully treated by plasma exchanges, with complete functional recovery within two months. The severity of this case justifies further consideration of pharmacokinetic interactions between palbociclib or other CDK-4-6 inhibitors and statins, which potentially increase the risk of an adverse event.

Lactic acidosis, a potential toxicity from drug-drug interaction related to concomitant ribociclib and metformin in preexisting renal insufficiency: A case report

Background

Ribociclib, one of the cyclin‐dependent kinases (CDK) 4 and 6 inhibitors, in combination with endocrine therapies has been approved in the treatment of hormonal receptor positive, HER‐2 negative metastatic breast cancer worldwide. Long‐term usage of ribociclib with concomitant drugs, potential drug–drug interaction may develop which can limit the therapeutic value of CDK4/6 inhibitor.

Case

A 62‐year‐old with history of non‐insulin dependent diabetic, dyslipidemia, and essential hypertension was diagnosed with HR‐positive, HER‐2 negative metastatic breast cancer and treated with fulvestrant plus ribociclib. Four weeks after administration, elevated serum creatinine was observed, and then severe lactic acidosis with acute respiratory failure was subsequently reported. Ribociclib and fulvestrant were temporarily discontinued. Three days after renal replacement therapy, her clinical was stabilized. Combination ribociclib with metformin resulted in high plasma metformin levels and dangerous consequences. Hence, special precaution should be considered during concomitant treatment with sensitive transporter substrates.

Conclusion

Metformin associated lactic acidosis may potentially occur after combination with ribocilib, an uncommon but lethal complication from the interaction of these drugs, especially in patients who had preexisting renal impairment.

Phloridzin Ameliorates Lipid Deposition in High-Fat-Diet-Fed Mice with Nonalcoholic Fatty Liver Disease via Inhibiting the mTORC1/SREBP-1c Pathway

We aimed to investigate whether phloridzin could alleviate nonalcoholic fatty liver disease (NAFLD) in mice, which was induced by feeding a high-fat diet (HFD). We initially analyzed the effect of phloridzin on alleviating HFD-induced NAFLD in C57BL/6J mice and oleic acid (OA)-stimulated human normal liver L-02 cells (L02). Then, we investigated the mechanism of phloridzin on the mTORC1/sterol-regulatory element-binding protein-1c (SREBP-1c) signaling pathway by siRNA analysis, qRT-PCR, flow cytometry, and western blot analysis in vivo and in vitro. The results revealed that phloridzin significantly inhibited the increase in body weight, alleviated abnormal lipid metabolism, and decreased lipid biosynthesis and insulin resistance. Moreover, phloridzin augmented the number of CD8⁺CD122⁺PD-1⁺ Tregs and CD4⁺FoxP3⁺ Tregs in HFD-fed C57BL/6J mice and HFD-fed aP2-SREBF1c mice and downregulated the mTORC1/SREBP-1c signaling pathway-related protein expressions in vivo and in vitro. Furthermore, phloridzin reduced the expression of SREBP-1c in SREBP-1c-RNAi-lentivirus-transfected L02 cells and reversed the SREBP-1c expression in HFD-fed aP2-SREBF1c transgenic mice. Phloridzin ameliorates lipid accumulation and insulin resistance via inhibiting the mTORC1/SREBP-1c pathways. These results indicated that phloridzin may actively ameliorate NAFLD.

Simvastatin in vitiligo: an update with recent review of the literature

Patients with vitiligo often seek medical attention, as it diminishes their quality of life resulting in significant morbidity. Several topical and systemic therapies are in vogue targeting the immunological aspect of this disease, but results are often unsatisfactory, and complete cure remains elusive. Recently, simvastatin, a 3-hydroxy-3-methylyglutaryl-coenzyme A (HMG-CoA) reductase inhibitor, is being evaluated for vitiligo management because of its multimodal action, easy availability, and low cost. The proposed multimodal actions range from anti-inflammatory, antioxidant, to immunomodulatory properties which may be of therapeutic benefit in vitiligo patients. The authors intend to evaluate the role of simvastatin as a novel therapeutic agent for vitiligo along with relevant review of literature.

Severe rhabdomyolysis induced by possible drug-drug interaction between Ribociclib and Simvastatin

INTRODUCTION

Drug-drug interactions with cyclin-dependent kinases inhibitors 4 and 6 (CDK4/6) are known and should be taken into account.

CASE REPORT

A 68-year-old woman, on prior Simvastatin therapy, developed severe rhabdomyolysis after three weeks of Ribociclib initiation. She showed general weakness with mobility problems and was admitted to our hospital.

MANAGEMENT AND OUTCOME

Ribociclib and Simvastatin were discontinued and the patient received intensive intravenous hydration. She finally recovered her mobility after two weeks.

DISCUSSION

We hypothesize that Simvastatin induced rhabdomyolysis by possible interaction with Ribociclib. Ribociclib is a strong inhibitor of CYP 3A4 and a potential inhibitor of OATP1B1 membrane transporter. Simvastatin plasma concentration may reach toxic levels due to Ribociclib inhibition. To assess the relevance of our hypothesis, we used the Drug Interaction Scale. With a total score of 7, the interaction is considered as "probable." Because of the high risk of severe rhabdomyolysis, the concomitant use of Simvastatin with Ribociclib should be avoided or otherwise careful monitoring of creatine kinase is warranted.

Targeting kinases with thymoquinone: a molecular approach to cancer therapeutics

Kinases are enzymes that are important for cellular functions, but their overexpression has strong connections with carcinogenesis, rendering them important targets for anticancer drugs. Thymoquinone (TQ) is a natural compound with proven anticancer activities, at least in preclinical studies. TQ can target several kinases, including phosphoinositide 3-kinase (PI3K), mitogen-activated protein kinase (MAPK), Janus kinase/signal transducers and activators of transcription (JAK/STAT), polo-like kinase 1 (PLK1), and tyrosine kinase in different cancer cells and animal models. Inhibiting the activity of kinases or suppressing their expression might be among the mechanisms of TQ anticancer activity. In this review, we discuss the role of TQ in kinase regulation in different cancer models.

Safety of the current drug treatments for vitiligo

Introduction: Vitiligo is an acquired depigmenting skin disorder adversely affecting the patient's quality of life. Despite the presence of several treatment modalities, ranging from medical to physical to surgical options, none is curative. Each modality has its own drawbacks and side effects. Thus, the treatment modality needs to be tailored for each individual patient taking into consideration the disease characteristics and also its efficacy and safety to obtain a favorable risk-benefit ratio.Areas covered: This review highlights the different treatment modalities utilized in vitiligo up until 4 November 2019 along with their adverse effects and contraindications, if any.Expert opinion: All the medications have their own adverse effects and contraindications. We have included the most commonly used topical corticosteroids, which may result in striae, cutaneous atrophy, and tachyphylaxis, to the recently introduced biologics, which may induce hypersensitivity reactions, systemic toxicities, and even malignancies. However, more long-term studies are needed to assess the safety of these medications, especially the newer ones, to provide a safe and effective treatment for this disorder.